As shown in FIG. 1, a seat 1 of a vehicle is composed of a seat cushion 1a and a seat back 1b. Seat cushion 1a can be adjusted to a predetermined position by a pumping device and seat back 1b can be adjusted to either angle forward or backward by a reclining device.
The pumping device is disposed in seat cushion 1a such that it can transmit power by connection with a link assembly of the seat cushion, and, as shown in FIG. 1, is actuated by a handle lever 3 that protrudes from a side of seat cushion 1a and moves up/down.
On the other hand, the pumping device is provided at a side in the seat, such that it is preferable for the pumping device to have a small size and volume in consideration of the space between the seat and the car body.
Further, the pumping device needs to smoothly operate when a user operates handle lever 3. In addition, the pumping device should have high operational sensitivity without generating noise in order to gain the consumers' confidence.
In particular, torque is exerted in the direction of moving down the seat cushion while a user is on the seat, such that the pumping device should not be suddenly actuated so that the seat does not jolt, even if the user operates handle lever 3 to move the seat cushion down.
Further, the pumping device should not be suddenly actuated so that the seat does not jolt, even if the user who is not in the seat operates handle lever 3 to move up the empty seat cushion.